|Publication number||US7001011 B2|
|Application number||US 10/636,204|
|Publication date||Feb 21, 2006|
|Filing date||Aug 8, 2003|
|Priority date||Apr 18, 2000|
|Also published as||DE60039312D1, US6659593, US6969473, US7007859, US7134608, US7370941, US7377621, US7387363, US7581818, US7591540, US7604325, US7645028, US7874640, US7980668, US8226214, US20040027421, US20040032463, US20040085400, US20060011738, US20060028512, US20060038853, US20060187261, US20070024675, US20080186361, US20080192090, US20080239008, US20090289997, US20100002054, US20100013890|
|Publication number||10636204, 636204, US 7001011 B2, US 7001011B2, US-B2-7001011, US7001011 B2, US7001011B2|
|Original Assignee||Silverbrook Research Pty Ltd|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (1), Referenced by (16), Classifications (17), Legal Events (7)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The present application is a continuation of U.S. application Ser. No. 10/204,211 filed on Aug. 19, 2002, now issued as U.S. Pat. No. 6,659,593, which is a National Phase application which is a 371 of PCT/AU00/00333 filed on Aug. 19, 2002, the entire contents of which are herein incorporated by reference.
The present invention relates to the field of Micro Electro Mechanical Systems (MEMS), and specifically inkjet printheads formed using MEMS technology.
MEMS devices are becoming increasingly popular and normally involve the creation of devices on the micron scale utilising semiconductor fabrication techniques. For a recent review on MEMS devices, reference is made to the article “The Broad Sweep of Integrated Micro Systems” by S. Tom Picraux and Paul J. McWhorter published December 1998 in IEEE Spectrum at pages 24 to 33.
MEMS manufacturing techniques are suitable for a wide range of devices, one class of which is inkjet printheads. One form of MEMS devices in popular use are inkjet printing devices in which ink is ejected from an ink ejection nozzle chamber. Many forms of inkjet devices are known.
Many different techniques on inkjet printing and associated devices have been invented. For a survey of the field, reference is made to an article by J Moore, “Non-Impact Printing: Introduction and Historical Perspective”, Output Hard Copy Devices, Editors R Dubeck and S Sherr, pages 207 to 220 (1988).
Recently, a new form of inkjet printing has been developed by the present applicant, which is referred to as Micro Electro Mechanical Inkjet (MEMJET) technology. In one form of the MEMJET technology, ink is ejected from an ink ejection nozzle chamber utilizing an electro mechanical actuator connected to a paddle or plunger which moves towards the ejection nozzle of the chamber for ejection of drops of ink from the ejection nozzle chamber.
The present invention concerns modifications to the structure of the paddle and/or the walls of the chamber to improve the efficiency of ejection of fluid from the chamber and subsequent refill.
In accordance with a first aspect of the invention there is provided a liquid ejection device including:
The first means to reduce fluid flow may include one or more baffles on a forward surface of the paddle to inhibit or deflect fluid flow.
The first means to reduce fluid flow may include an upturned portion of the peripheral region of the forward surface.
The first means to reduce fluid flow may include at least one depression, groove projection, ridge or the like on the forward surface of the paddle.
The projection or depression may comprise a truncated pyramid.
The ridge or groove may be linear, elliptical, circular, arcuate or any appropriate shape.
Where multiple ridges or grooves are provided they may be parallel, concentric or intersecting.
The forward surface of the wall of the chamber adjacent the fluid inlet port may also be provided with second means to reduce fluid flow through the aperture toward the inlet port as the paddle moves from the rest state to the ejection state.
The second means may be an angling into the chamber of the forward surface of the wall of the chamber around the fluid inlet port.
The rear surface of the paddle may include third means to encourage fluid flow into the chamber as the paddle moves from the ejection state to the rest state.
The third means may be an angling into the chamber of the rear surface of the paddle.
The angling of the rear surface may be limited to the peripheral region of the rear surface.
The port may be configured to encourage fluid flow into the chamber as the paddle moves from the ejection state to the rest state.
The surface of the wall of the inlet port adjacent to paddle may be angled into the chamber such that the aperture decreases in area toward the chamber.
The paddle may be a constant thickness.
In another aspect the invention provides a liquid ejection device including:
All of the peripheral portion may extend at a constant angle to the forward direction or it may be curved.
The central portion may extend generally perpendicular to the first direction. The paddle may be of a constant thickness.
The forward surface of the wall of the chamber defining the inlet port may be planar but is preferably angled upward into the chamber.
The inlet port is preferably defined by the wall of the chamber extending over the end of a fluid passage way. At least part of the walls of the chamber are preferably angled toward the chamber to form a convergent inlet in the downstream direction.
In another broad form the invention provides a liquid ejection device including:
In another aspect of the invention also provides a method of manufacturing a micro mechanical device which includes a movable paddle, the method utilising semi conductor fabrication techniques and including the steps of:
The step b) may include depositing a one or more additional layers of sacrificial material on selected parts of the second layer. The additional layer or layers may be deposited on all of the second layer or only on part of the second layer. The paddle so formed may thus be multi-levelled.
Preferably the sacrificial material is a polyimide.
Preferably the second layer is deposited to lie under the peripheral region of the as yet unformed paddle.
Notwithstanding any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
In the preferred embodiment, a compact form of liquid ejection device is provided which utilises a thermal bend actuator to eject ink from a nozzle chamber.
As shown in
The ink is ejected from a nozzle chamber 2 by means of a thermal actuator 7 which is rigidly interconnected to a nozzle paddle 5. The thermal actuator 7 comprises two arms 8, 9 with the bottom arm 9 being interconnected to an electrical current source so as to provide conductive heating of the bottom arm 9. When it is desired to eject a drop from the nozzle chamber 2, the bottom arm 9 is heated so as to cause rapid expansion of this arm 9 relative to the top arm 8. The rapid expansion in turn causes a rapid upward movement of the paddle 5 within the nozzle chamber 2. This initial movement causes a substantial increase in pressure within the nozzle chamber 2 which in turn causes ink to flow out of the nozzle 11 causing the meniscus 10 to bulge. Subsequently, the current to the heater 9 is turned off so as to cause the paddle 5 to begin to return to its original position. This results in a substantial decrease in the pressure within the nozzle chamber 2. The forward momentum of the ink outside the nozzle rim 11 results in a necking and breaking of the meniscus so as to form a meniscus and a droplet of ink 18 (see FIG. 4). The droplet 18 continues forward onto the ink print medium as the paddle returns toward its rest state. The meniscus then returns to the position shown in
Whilst the peripheral portion 13 of the chamber wall defining the inlet port is also angled upwards, it will be appreciated that this is not essential.
Subsequently, the thermal actuator is deactivated and the nozzle paddle rapidly starts returning to its rest position as illustrated in FIG. 4. This results in a general reduction in the pressure within the nozzle chamber 2 which in turn results in a general necking and breaking of a drop 18. The meniscus 10 is drawn into the chamber 2 and the returns to the position shown in
The profiling of the lower surfaces of the edge regions 12, 13 also assists in channelling fluid flow into the top portion of the nozzle chamber compared to simple planar surfaces.
The rapid refill of the nozzle chamber in turn allows for higher speed operation.
Process of Manufacture
The arrangement in
It would be appreciated by a person skilled in the art that numerous variations and/or modifications may be made to the present invention as shown in the specific embodiment without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects to be illustrative and not restrictive.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US6827425 *||Aug 11, 2003||Dec 7, 2004||Silverbrook Research Pty Ltd||Liquid ejection device|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US7128403 *||Jun 8, 2004||Oct 31, 2006||Samsung Electronics Co., Ltd.||Microactuator and fluid transfer apparatus using the same|
|US7370941 *||Jul 11, 2005||May 13, 2008||Silverbrook Research Pty Ltd||Fluid chamber configuration within an inkjet printhead|
|US7377621 *||Sep 30, 2005||May 27, 2008||Silverbrook Research Pty Ltd||Fluid chamber configuration within an inkjet printhead|
|US7591540||Apr 16, 2008||Sep 22, 2009||Silverbrook Research Pty Ltd||Ink ejection arrangement having cooperating chamber wall edge portions and paddle edge portions|
|US7645028||Apr 3, 2008||Jan 12, 2010||Silverbrook Research Pty Ltd||Ink ejection nozzle with a paddle having a series of protrusions to reduce outward ink flow|
|US7980668 *||Sep 13, 2009||Jul 19, 2011||Silverbrook Research Pty Ltd||Ejection arrangement for printhead nozzle|
|US8069565||Feb 11, 2010||Dec 6, 2011||Silverbrook Research Pty Ltd||Method of forming a nozzle chamber incorporating an ink ejection paddle and nozzle chamber rim|
|US8226214||Sep 21, 2009||Jul 24, 2012||Zamtec Limited||Inkjet printhead with internal rim in ink chamber|
|US20040252164 *||Jun 8, 2004||Dec 16, 2004||Samsung Electronics Co., Ltd.||Microactuator and fluid transfer apparatus using the same|
|US20060038853 *||Sep 30, 2005||Feb 23, 2006||Silverbrook Research Pty Ltd||Fluid chamber configuration within an inkjet printhead|
|US20060187261 *||Jul 11, 2005||Aug 24, 2006||Silverbrook Research Pty Ltd||Fluid chamber configuration within an inkjet printhead|
|US20080186361 *||Apr 3, 2008||Aug 7, 2008||Silverbrook Research Pty Ltd||Ink Ejection Nozzle With A Paddle Having A Series Of Protrusions To Reduce Outward Ink Flow|
|US20080192090 *||Apr 16, 2008||Aug 14, 2008||Silverbrook Research Pty Ltd||Ink ejection arrangement having cooperating chamber wall edge portions and paddle edge portions|
|US20100002054 *||Sep 13, 2009||Jan 7, 2010||Silverbrook Research Pty Ltd||Ejection arrangement for printhead nozzle|
|US20100013890 *||Sep 21, 2009||Jan 21, 2010||Silverbrook Research Pty Ltd||Inkjet Printhead With Internal Rim In Ink Chamber|
|US20100140216 *||Feb 11, 2010||Jun 10, 2010||Silverbrook Research Pty Ltd||Method Of Forming A Nozzle Chamber Incorporating An Ink Ejection Paddle And Nozzle Chamber Rim|
|International Classification||B41J2/04, B41J2/14|
|Cooperative Classification||B41J2/1626, B41J2/1648, B41J2/1645, B41J2/1639, B41J2/14427, B41J2/1635, B41J2/1631|
|European Classification||B41J2/16M4, B41J2/16M8S, B41J2/16M7S, B41J2/16M3, B41J2/16M6, B41J2/14S, B41J2/16S|
|Aug 8, 2003||AS||Assignment|
Owner name: SILVERBROOK RESEARCH PTY. LTD., AUSTRALIA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SILVERBROOK, KIA;REEL/FRAME:014378/0790
Effective date: 20021218
|Aug 1, 2006||CC||Certificate of correction|
|Aug 4, 2009||FPAY||Fee payment|
Year of fee payment: 4
|Jul 13, 2012||AS||Assignment|
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SILVERBROOK RESEARCH PTY. LIMITED AND CLAMATE PTY LIMITED;REEL/FRAME:028542/0756
Effective date: 20120503
Owner name: ZAMTEC LIMITED, IRELAND
|Oct 4, 2013||REMI||Maintenance fee reminder mailed|
|Feb 21, 2014||LAPS||Lapse for failure to pay maintenance fees|
|Apr 15, 2014||FP||Expired due to failure to pay maintenance fee|
Effective date: 20140221